EP0855695B1 - Fallboard for keyboardinstrument - Google Patents

Abstract

The free-run component is arranged in the extension of the pivot axis (13) of the keyboard flap (2). The damping component permits an unlimited rotary angle and is formed by a housing filled with fluid in which a part rotatable in relation to it is braked by fluid friction. The damping and free-run components are integrated to form a common part (4,6). The integrated part is incorporated on one or both sides (20) of the keyboard flap at the position of a hinge or rotary bearing. A hinge component (4) fixed to the housing has a cylindrical housing (6) with a face-side fixture flange (7). The cylindrical housing part is inserted in a correspondingly dimensioned blind hole of the housing wall.

Description

The invention relates to a housing-side part of a hinge element for a key flap for keyboard instruments, in particular for wings with a damper damping element, according to first part / upper part of claim 1 (US-A-5 056 396).

To protect the keyboard of a keyboard musical instrument from dust is common a key flap is available, the keyboard when not in use covers and for playing around an axis parallel to the row of keys in a about vertical position can be pivoted. In this open position however, the flap is in an extremely unstable condition. It does fall usually not by itself, but a slight, careless one is sufficient Touch to unbalance the flap so that it is due to their not inconsiderable weight falls down and the fingers the pianist is stuck and possibly even injured.

For this reason, according to DE-U-295 20 529 a damper device for the folding movement of a keyboard flap is provided be so that when swiveling it does not with the full force of its weight falls, but is braked and thus with more constant, slower Speed swings down. For this purpose, the area is one front hinge on the swiveling receptacle for the key flap an angle iron with a radial with respect to the pivot axis and a adjoining tangential legs. On the free one The end of the tangential leg is the piston rod of a closed, hydraulic one Working cylinder articulated, with its rear end over another pivot bearing with a mounting plate to fix on the Instrument housing is connected The working cylinder is through in its length a working medium is braked adjustable and thereby dampens the flap movement from. This arrangement can cause the key flap to drop suddenly be avoided; nevertheless, the problem arises here that the working cylinder has a dampening effect in both directions, so that the pivoting up of the key flap is braked. Therefore, the Key flap slowly before playing and under high physical exertion be swung up, which proves to be extremely cumbersome the construction known from the above utility model is relatively complex and takes up a large volume because of the working cylinder, what is unfavorable for some instruments.

From US-A-5 635 655 and WO-A-9 520 211 is a key flap oil damper known that works on the basis of a liquid valve. Through there described valve mechanisms is achieved that when opening the Key flap viscous liquid in one chamber free or with less Resistance flows or can be moved than when the key flap is closed.

In EP-A-0 289 954 a damping mechanism for a key flap is disclosed described, the use of a wound around the hinge axis Coil spring is based. One of their ends is with a rotatable one hollow cylindrical housing firmly connected. This is what happens with a Closing movement to press the coil spring onto the shaft of the Hinge axis, which increases the friction with increasing closing movement becomes. When it is opened, the spiral spring is expanded radially in reverse. to Increasing the friction between the inside of the housing and the Hinge axis stem are still in the annular gap between the two parts highly viscous fabrics introduced.

From US-A-5 056 396 a generic, housing-side part of a Hinge element known. The opening / closing device described for the piano key flap works with an oil damper that one with Brake fluid filled oil chamber. On a shaft of the oil damper corresponding to the key hinge axis is a lever element with a Liquid valve articulated. When the flap opens, it will Lever element moved in the oil chamber. Oil can flow freely through a Through hole in the lever element flow without the user significant fluid resistance arises when the flap is opened. To the The lever element will close in the opposite direction within the Oil chamber swiveled. The valve is the one mentioned Through hole closed. Only small ones are left for the flow Openings in a side wall are available.

In contrast, it is an object of the invention, the key flap hinges Construction of the housing-side part as simple and space-saving as possible shape. The solution specified in claim 1, the housing-side part proposed a hinge element for the key flap. Expedient, advantageous embodiments of this invention result from the dependent Claims.

According to the invention is in addition to the damping Element provided a freewheel element, which has an undamped opening movement allows. Such freewheel elements cause one direction of movement a rigid coupling between the two connection elements of the freewheel element, while in the other direction of rotation the coupling is completely released is. Due to this function, it is possible to reduce the braking effect of a damping element for the opening movement, so that none increased strength is necessary.

The invention further provides that the freewheel element in the extension the pivot axis of the key flap is arranged. This creates an additional Transmission saved, so that there is an inconspicuous appearance is also the construction is very simple and therefore less prone to failure.

It is part of an invention training that the damping element an unlimited Allows rotation angle. Due to the freewheel element the damping element is not actuated during the opening movement of the key flap and therefore remains in its starting position. When closing the flap a part of the damping element is, however, taken with it Braking effect is transferred to the key flap. The damping element therefore leads constantly and only one rotation in the same Direction out; there is no resetting movement. That is why it is essential in the context of this training required to use such a damping element, which allows an unlimited angle of rotation.

For this purpose, a damping element is particularly suitable, which according to the invention has one with one Fluid-filled housing is formed, in which, in contrast, a rotatable Part is slowed down by fluid friction. Unlike a hydraulic one Cylinder, whose linear displacement movement is naturally limited the relative movement in the damping element directly damped by a braked rotating part. This also becomes a hydraulic cylinder completely unnecessary, which further simplifies the construction can be caused in particular by the fact that in the Housing arranged, rotatable part in the form of a roller or a paddle wheel has its shell or blades close to the inside of the housing reach up, where a viscous brake fluid is filled, for example silicone adheres firmly to the inner surface of the housing and thus at least partially pass through the slot formed by the shell or the blades got to.

A further development of the invention, which is both alternative and cumulative the fluid damping described above can be realized by one or more elastic elements, which are located between the housing of the damping element and a part that is rotatable relative to it and generate a braking effect by friction. such, Above all, elastic elements offer the possibility of braking Change the contact pressure. This additional property allows it, a standardized damping element for a variety of different Key flaps to use, both for lighter key flaps with a polyester cover as well as with heavier, satined key flaps.

The construction can be simplified by being elastic Element a ring is used. This can preferably be in a rotating Deepening of the rotatable part inserted and held in it as well be led. The reason of such a groove-like depression brings the radial outward counterforce for the ring from the inside of the housing exerted central force.

By designing the elastic ring as an O-ring, it receives an optimal one Cross section with a high elasticity, because here in the edge areas a cross-sectionally approximately square or rectangular slot deformation areas to accommodate bulges of the O-ring. Also this favors the assembly of such a damping element, the housing being an optimal contact surface when pushed onto the O-ring finds.

The invention can be further developed in such a way that the approximately perpendicular to the Boundary surfaces of the recess receiving the O-ring to increase the radial contact forces acting on each other are designed to be adjustable. By this side edges of the groove-shaped recess are approached to one another, the O-ring strives to this Crushing deformation in the axial direction due to an alternative extension in the radial direction Direction to compensate. With this tendency towards radial stretching the contact forces acting on the inside of the housing and the bottom of the groove increased so that the frictional forces also increase. As a result, the braking or damping effect.

In order to bring the two sides of the groove-like recess closer together, one can Pressure plate can be used, which is a boundary surface of the depression for forms the O-ring and on the rotatable part, which is the opposite Boundary surface of the depression forms, non-rotatable, but in the direction of Axis of rotation is fixed movably. The pressure plate could also be on the housing part non-rotatably, but arranged movably in the direction of the axis of rotation in such a case, however, there would be an unfavorable use of space for the adjustment mechanism. With a non-rotatable fixing on the rotatable part, however, the adjustment mechanism within the the latter may be arranged.

The adjustment mechanism preferably comprises a central screw, which the rotatable part and / or a disc fixed in the same with its shaft reaches through and screwed into a threaded hole in the pressure plate is. Such a screw is used to hold the pressure plate on the rotatable part and thus the groove-shaped recess cross-section to reduce, thereby a squeezing effect on the inserted O-ring exercise and thereby increase its frictional force. Will the The screw, on the other hand, moves in the loosening direction due to the elasticity of the O-ring no additional mechanics required to get the pressure plate back on to return to their starting position. In this respect, the result is extremely simple Construction, which also has a continuous adjustment of the damping effect allowed. The screw head can have a hexagonal cross section Recess for inserting an Allen key. Therefor is an outwardly opening channel within the axis of rotation of the damping element intended. To make a fine adjustment even in the sidewall of one To allow grand piano or piano already built-in damping element the mouth of this channel on that end of the damping element are located on which the key flap is detachably attached.

Fig. 1

eine perspektivische Darstellung einer nicht die Erfindung betreffenden Tastenklappe in nahezu vollständig hochgeschwenkter Position, teilweise abgebrochen,

Fig.2

einen Schnitt durch die Fig. 1 entlang der Linie II - II,

Fig. 3

den erfindungsgemäßen gehäuseseitigen Teil eines Scharnierelements,

Fig. 4

das klappenseitige Pendant zu dem gehäuseseitigen Schamierteil aus Fig. 3,

Fig. 5

einen Schnitt durch die Fig. 3 entlang der Linie V - V, sowie

Fig.6

eine der Fig. 5 entsprechende Darstellung einer abweichenden Ausführungsform der Erfindung.

Further details, features and advantages on the basis of the invention result from the following description of a preferred embodiment of the invention and from the drawing. This shows in:

Fig. 1

2 shows a perspective illustration of a key flap not relating to the invention in an almost completely pivoted-up position, partially broken off,

Fig.2

2 shows a section through FIG. 1 along the line II-II,

Fig. 3

the housing-side part of a hinge element according to the invention,

Fig. 4

the flap-side counterpart to the housing-side hinge part from FIG. 3,

Fig. 5

a section through Fig. 3 along the line V - V, and

Figure 6

a representation corresponding to FIG. 5 of a different embodiment of the invention.

1 is the side wall 1 to the left of the keyboard, not shown to see a wing on which a key flap 2 by means of a Hinge element 3 is rotatably mounted. Like Fig. 2 more clearly shows, the hinge element 3 consists of a housing-side part 4 and a flap-fixed part 5 together. These two parts are shown in FIGS. 3 and 4 each shown separately.

3 shows the part 4 of the hinge element which is fixed to the housing and which is cylindrical Has housing 6 with an end mounting flange 7. The cylindrical Housing part 6 is in a correspondingly dimensioned blind hole 8 of the housing wall 1 inserted, and with four fastening screws 9, which each pass through an opening 10 of the mounting flange 7, immovable established. The rear part 11 of the housing 6 is designed as a detachable cap 11, through which the mechanics are accessible.

The mechanical connection to the key flap 2 is made by means of an in the area the end of the hinge element part 4 provided with the flange 7 Rotary body 30, with an extension 15 through a central recess this end face is accessible for connecting the key flap 2. This rotating body is non-rotatable with a concentric to the housing 6 Axis 31 coupled, which this to the opposite end face 11th interspersed. In addition to the rotating part 30, there is a roller freewheel 32 on the shaft 31 set, the outer periphery of which carries a roller body 33 which covers the area between the outer circumference of the roller freewheel 32 and the inside of the housing 6 almost completely filled. Only a small amount remains Gap 34 in the area of the inside of the housing 6, which with silicone as Brake fluid is filled. An O-ring 35 seals the area for the brake fluid towards the front of the housing 6, which is open towards the outside.

The extension 15 is of a circular ring formed on the mounting flange 7 16 surrounded, which is approximately flush with the front side 17 of the front Extension 15 completes, however, compared to the mounting flange 5 by Protrudes 5 mm. This circular ring 16 is on its top by a Slot 18 interrupted, which is in a corresponding relative position of the extension 15 in the form of a groove 19 of this extension 15 up to the axis of rotation 13 of the housing 6 continues. This makes it possible for a corresponding Rotary position of the extension 15 one on the end face 20 of the flap Insert 2 immovably fixed pin 21 through the slot 18 into the groove 19. The pin 21 is formed on a metal plate 22, which by means of two Screws 23 in a recess 24 of the end face open towards the rear of the flap 20 of the flap 2 is screwed on. The pin 21 has an elongated cross section with two mutually parallel side surfaces 25 which are approximately parallel to the Flap base 26 are oriented. The distance between these two side surfaces 25 corresponds approximately to the width of the groove 19, so that in the inserted state, as shown in Fig. 2, a positive and thus twist-proof Coupling between the extension 15 and the flap 2 results

If the flap 2 is now pivoted upwards in the direction of the arrow 27, then the Coupling of the freewheel element 32 is released and without a relative rotation between the extension 15 and the inner housing of the damping element, not shown 6 the flap 2 can be opened effortlessly. If the flap 2 but then closed 28, the freewheel element 32 locks, so that the only possibility of movement through the damping element 34 is made possible. This sets the movement 28 due to the silicone medium however, a high braking force opposes and the flap 2 can consequently only be moved slowly. The flap 2 is more than about 45 ° in Has been pivoted in the direction of arrow 28, so is the flap weight caused torque sufficient to ensure an automatic closing 28.

The embodiment according to FIG. 6 differs from that described above exclusively with regard to the hinge element part 40 fixed to the housing, while the flap-fixed part 5 can be kept unchanged.

The housing 41 of the hinge element 40 corresponds externally completely to the housing part 6 of the embodiment shown in Figure 5, except that Instead of a hood-like, rear part 11, a flat cover 42 in the cylindrical housing inserted and into a groove-shaped recess broken ring 43 is prevented from slipping out. The lid 42 can be used to pass parts of the internal mechanics with a central one Recess 44 or bulge (not shown) may be provided.

The rotational body 30 according to FIG. 5 finds its correspondence with the housing-side part 40 according to FIG. 6 in the form of the two, approximately annular parts 45, 46. Here, the part 45 simultaneously takes over the function of the extension 15 and forms a groove-like recess 19 for receiving a pin 41 of the key flap 2. Part 46 is of part 45 only for the purpose of simpler Assembled separately. In addition, the mounting flange 7th of the housing 41 facing boundary surface between the two rotating bodies 45, 46 expanded in cross section and takes a sealing O-ring 47, which, like the O-ring 35 according to FIG. 5, has the task within of the hinge element 40 located brake fluid before flowing out to preserve. The rotating part 45 is concentric on one in the housing 41 recorded shaft 48 immovably, and these two parts 45, 48th each have a central bore 49 aligned with one another.

As in the arrangement according to FIG. 5, there is a roller freewheel 32 on the shaft 48 set, the outer periphery of which carries a roller body 50, the area between the outer circumference of the roller freewheel 32 and the inside of the housing 41 fills almost completely, except for a small gap 34 in the area the inside of the housing 41, in which there is silicone as the brake fluid. Silicone is relatively viscous and can be applied to the outer surface before assembly of the roller body 50 are applied. After assembly and during during operation, the silicone cannot be in the area due to the sealing ring 47 of the mounting flange 7 emerge from the housing 41.

The roller body 50 does not extend to the opposite end plate 42, but in between is a disc 51, which on her the lid 42 adjacent side a central recess 52 for receiving a second sealing ring 53, which the silicone emerges from the central opening 44 in the lid 42 prevents. Between the roller body 50 and the pressure plate 51 there is a small air gap 54 which in the area of the housing 41 to form a circumferential, cross-section For example, rectangular groove 55 expanded. This groove 55 takes an elastic Ring 56, which is preferably designed as an O-ring, and its diameter corresponds approximately to the depth of the groove 55 and the maximum width thereof. Two or more, eccentric, preferably diametrically arranged, with each other aligned holes 57 in the roller body on the one hand and the pressure plate 51 on the other hand each take a bolt 58 so that the pressure plate 51 traces any rotational movement of the roller body 50.

The pressure plate 51 will reduce the air gap 54 to the roller body 50 approached, the cross-section of the all-round is reduced Groove 55, and the O-ring 56 is squeezed and settles with increased frictional force on the inside 58 of the housing 41. This will cause friction of the damping element 40 increases, and the closing movement of the key flap under its own weight is slowed down at this closing speed depending on the weight of the key flap, it is possible to set a Mechanism for adjusting the distance between the roller body 50 and the pressure plate 51 is provided. This mechanism consists of a machine screw 59, which is supported by a washer 60 with its head 61 and is screwed into a threaded bore 62 of the pressure plate 51 becomes. Since the washer 60 is in the region of the end face on the cover side of the roller body 50 all around, supported inwardly projecting shoulder is, by a suitable rotation of the screw 61, the pressure plate 51 pulled to the roller body 50. If the screw 59 in actuated in the opposite direction, the initially deformed O-ring presses its elasticity, the pressure plate 51 again away from the roller body 50 the original position back.

The head 61 of the screw 59 is in a cross-sectional extension of the shaft 48 recorded and has a cross-sectional hexagonal depression at the top, in which a suitable Allen key through the central Openings 49 can be inserted through to the screw 59 around to twist the desired dimension. This can also be done when the Hinge element part 40 happen, for which purpose only the key flap 2 temporarily must be removed. In this respect, the damping mechanism can be readjusted exactly after any length of time.

Claims (9)

1. Part (4, 40), associated with the housing, of a hinge element (3) for a keyboard lid (2) for keyboard instruments, in particular grand pianos, which lid is displaceable in order to be opened and closed in pivoting motions (27, 28) about a hinge shaft (31; 48) extending parallel to the keys, wherein the hinge element (3) is formed with the part (4) connectable rigidly to an instrument housing or fixable to the housing and with a part (5) connected to the keyboard lid and connectable to the part (4) associated with the housing, and the part (4) associated with the housing has, inside its own hinge housing part (6; 41) a rotary body (30; 45, 46) mounted direct non-rotatably on the hinge shaft (31) and a damping element for the pivoting motions (28) at least for closing of the lid (2), to which end the hinge housing (6; 41) is filled with a braking fluid in order to achieve fluid friction, characterised in that the damping element has a roller body (33; 50) disposed coaxial to the rotary body (30), which roller body is exposed for braking to the fluid friction by the braking fluid inside the hinge housing part (6; 41) and is coupled to the hinge shaft (31, 48) via a freewheel element (32), which with respect to the roller body (33) permits movements (27) of the hinge shaft (31, 48) for undamped opening of the lid (2).
2. Part (4, 40) associated with the housing according to claim 1, characterised in that the damping element has between the hinge housing part (6; 41) and the roller body (33; 50) located therein a gap (34) which is filled with the braking fluid and in which the roller body (33; 50) and optionally the rotary body (30; 45, 46) is braked by the fluid friction, an unlimited angle of rotation being permitted.
3. Part (4, 40) associated with the housing according to claim 1 or 2, characterised by one or more resilient elements (35; 36) between the hinge housing part (6; 41) and the roller body (33; 50) located therein for generating a braking effect by friction.
4. Part (4, 40) associated with the housing according to claim 2 and 3, characterised in that the resilient element (35; 56) is formed as a ring (35; 56) or O-ring extending in the gap (34).
5. Part (4, 40) associated with the housing according to claim 4, characterised in that the resilient ring (35; 56) is arranged so as to encompass the roller body (33; 50).
6. Part (4, 40) associated with the housing according to claim 4 or 5, characterised in that the resilient ring (35; 56) is received in a continuous recess or groove (55) in the roller body (50).
7. Part (4, 40) associated with the housing according to claim 6, characterised in that the recess or groove (55) has edging faces extending roughly vertically to the hinge shaft (31, 48), which are adjustable towards one another in order to increase a pressure force for the ring (56) or O-ring.
8. Part (4, 40) associated with the housing according to claim 7, characterised by a pressure disc (51), which forms an edging face of the recess or groove (55) for the ring (56) and on the roller body (50), which forms the opposite edging face of the recess or groove (55), and which is non-rotatable but movably fixed in the direction of the hinge shaft (48).
9. Part (4, 40) associated with the housing according to claim 8, characterised by a central screw (59), which penetrates with a shank the roller body (50) and/or a disc (60) formed in the same and is screwed into a threaded bore (32) of the pressure disc (51).

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